Structure of header-tank for a heat exchanger

ABSTRACT

The structure of header-tank for a heat exchanger comprises a plurality of tubes which are arranged in a row along an air-blowing direction to be spaced apart from each other at a certain intervals; fins which are interposed between the tubes so as to increase a heat exchange surface area with respect to air flowing between the tubes; and a pair of header-tanks which comprises a header having a tube insertion hole and a tank coupled with the header and in which heat exchange medium is flowed, wherein the header is bent at a surface, in which the tube insertion hole is formed, so as to form a bending portion in a height direction, and the bending portion is formed with a plurality of taps  5 , and the tank is formed with a coupling portion coupled to the bending portion of the header, and a coupling groove which is recessed inside tank at the same position as the tap along a longitudinal direction and in which the tap is bent and inserted.

TECHNICAL FIELD

The present invention relates to a structure of header-tank for a heat exchanger, more particularly, to a structure of header-tank for a heat exchanger, in which a binding force between a header and a tank of a heat exchanger is increased, thereby increasing durability and also nursing materials upon a manufacturing process.

BACKGROUND ART

In the automobile industry, as general concerns about energy and environment are increased globally, the efficiency in each part including fuel efficiency has been steadily improved, and the external appearance of a vehicle has been also diversified in order to satisfy various demands of customers. According to such a tendency, research and development on lighter weight, smaller size and multi-function of each vehicle component has been carried out. Particularly, in an air-conditioning unit for a vehicle, since it is generally difficult to secure an enough space in an engine room, there have been many efforts to manufacture a heat exchange system having a small size and high efficiency.

Meanwhile, the heat exchange system generally includes an evaporator for absorbing heat from a peripheral portion, a compressor for compressing refrigerant, a condenser for radiating heat to a peripheral portion, and an expansion valve for expanding the refrigerant. In an air-conditioning system, the gaseous refrigerant introduced from the evaporator to the compressor is compressed at a high pressure and high temperature, and the compressed gaseous refrigerant radiates liquefaction heat to a peripheral portion while passing through the condenser so as to be liquefied, and the liquefied refrigerant is passed through the expansion valve so as to be a low pressure low temperature wet vapor state and then introduced again into the evaporator so as to absorb vaporization heat from a peripheral portion while the wet vapor refrigerant is vaporized, and thus peripheral air is cooled.

The condenser, evaporator, etc. used in the air-conditioning system are typical heat exchangers, and many studies have been made on efficiently performing the heat exchange between air outside the heat exchanger and heat exchange medium, i.e., refrigerant inside the heat exchanger. FIGS. 1 a to 1 c are perspective views of conventional heat exchangers, wherein FIGS. 1 a and 1 b show a heat exchanger in which tubes are arranged in single file and FIG. 1 c shows a heat exchanger in which tubes are arranged in two files. As shown in the drawings, the heat exchanger includes a plurality of tubes 20 which are arranged in a row along an air-blowing direction to be spaced apart from each other at a certain intervals and in which a heat exchange medium is flowed; fins 30 which are interposed between the tubes 20 so as to increase a heat exchange surface area with respect to air flowing between the tubes 20; a pair of header-tanks which are respectively formed by coupling a header 11′ and a tank 12′ and coupled to both ends of the tubes 20 so that the heat exchange medium is flowed therethrough and of which both ends in the longitudinal direction are closed by an end cap 14. The header 11′ is formed into a U-shape, and a plurality of tube insertion holes 14′ are formed at a surface facing an opened surface of the header 11′ to be extended in the transverse direction and arranged in the longitudinal direction. Also the tank 12′ is formed into a U-shape, an opened surface of the tank 12′ is coupled to the opened surface of the header 11′, and a plurality of taps 15′ are formed along both edge portions of the opened surface of the tank 12′. The taps 15′ formed at the tank 12′ are bent to support the header 11′ when the tank 12′ is coupled to the header 11′, thereby maintaining the binding between the header 11′ and the tank 12′.

FIG. 1 a shows that the taps 15′ are formed at the edge portions of the tank 12′. However, in case that edge portions of the header 11′ are placed outside the edge portions of the tank 12′, the taps 15′ may be formed at the edge portions of the header 11′.

FIG. 2 is a representative view of Japanese Patent Publication No. 2002-206889 (hereinafter, called as cited invention) showing a conventional header-tank having the above-motioned structure.

However, in the cited invention in which the tank is adopted to support the header by bending the taps and thus maintain the binding, it is obvious that the binding force by the tap is applied only in the height direction (referring to directions in FIG. 1 a). That is, in the header-tank structure of FIGS. 1 a and 2, there is a problem that the binding force can not be applied, if the header and the tank are disclosed in the longitudinal direction.

Furthermore, the conventional taps has to be extended over a surface of the header or the tank (if the taps are formed at the tank, it is the header, and if the taps are formed at the header, it is the tank). In this case, only the tap portions are left, and then the rest portions are cut and abandoned. If a length of the each tap is reduced in order to save the materials, since the binding force is lowered, it is limited to reduce the length of the tap. Therefore, there is a problem that a serious waste of the materials is occurred.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a structure of header-tank for a heat exchanger, which can increase a binding force between a header and a tank of a heat exchanger so as to increase durability, improve a binding strength between the header and the tank and also nurse materials upon a manufacturing process.

To achieve the above object, the present invention provides a structure of header-tank for a heat exchanger, comprising a plurality of tubes 20 which are arranged in a row along an air-blowing direction to be spaced apart from each other at a certain intervals; fins 30 which are interposed between the tubes 20 so as to increase a heat exchange surface area with respect to air flowing between the tubes 20; and a pair of header-tanks which comprises a header 11 having a tube insertion hole 13 and a tank 12 coupled with the header 11 and in which heat exchange medium is flowed, wherein the header 11 is bent at a surface, in which the tube insertion hole 13 is formed, so as to form a bending portion 18 in a height direction, and the bending portion is formed with a plurality of taps 15, and the tank 12 is formed with a coupling portion 19 coupled to the bending portion 18 of the header 11, and a coupling groove 16 which is recessed inside tank 12 at the same position as the tap 15 along a longitudinal direction and in which the tap 15 is bent and inserted.

Preferably, the header 11 is formed by bending a single plate material so that the bending portion 18 is formed at both ends, and provided with a partition wall extended in the height direction at a center portion thereof so as to form a passage in two files.

Further, at least one or more auxiliary groove 16 a is formed between the adjacent coupling grooves 16, and the auxiliary groove 16 a has the same shape as the coupling groove 16, and the auxiliary groove 16 a is formed to be recessed inside the tank 12 along a circumferential surface of the tank 12.

Further, the header further comprises a restricting protrusion 17 which is protruded inside the header 11 so as to restrict insertion of an end of the coupling portion 19 of the tank 12 to a predetermined depth when the tank 12 is inserted to the bending portion 18 of the header 11.

Further, the restricting protrusion 17 is formed by press-forming.

Further, the restricting protrusion 17 is formed between the taps 15 of the bending portion 18.

Further, the restricting protrusion 17 is formed at a lower side of the tap 15 in the longitudinal direction.

Further, the tap 15 and the restricting protrusion 17 are formed at an area of the bending portion 18, which is placed between the tube insertion holes 13 in the longitudinal direction.

Further, the coupling groove 16 is connected with an outer surface of the tank 12 through an inclined surface S.

Further, the inclined surface S surrounding an end of the coupling groove 16 forms a hook portion 16 b which is contacted with the bent tap 15 so as to prevent the header 11 and the tank 12 from being separated.

Further, an end of the bending portion 18 is placed at a lower side of the inclined surface S and the coupling groove 16 so as to prevent the bending portion 18 from being overlapped with a lower portion of the inclined surface S and the coupling groove 16 of the tank 12.

Further, the bending portion is formed with a plane contact portion G having a predetermined distance d, which is provided between an end of the bending portion and an end of the restricting protrusion 17.

Further, the tap 15 is formed to be equal to or greater than a width R of the inclined surface S.

The present invention further, provides a structure of header-tank for a heat exchanger, comprising a plurality of tubes 20 which are arranged in a row along an air-blowing direction to be spaced apart from each other at a certain intervals; fins 30 which are interposed between the tubes 20 so as to increase a heat exchange surface area with respect to air flowing between the tubes 20; and a pair of header-tanks which comprises a header 11A having a tube insertion hole 13 and a tank 12A coupled with the header 11A and in which heat exchange medium is flowed, wherein the header 11A is bent at a surface, in which the tube insertion hole 13 is formed, so as to form a bending portion 18A in a height direction, and the bending portion 18A is formed with a plurality of coupling groove 16A formed to be recessed inside the header 11A, and the tank 12 is formed with a coupling portion 19A coupled to the bending portion 18A of the header 11A, and a tap 15A which is formed at the same position as the coupling groove 16A along a longitudinal direction so as to be bent to and inserted into the coupling groove 16A.

Further, the header 11A is formed by bending a single plate material so that the bending portion 18A is formed at both ends, and provided with a partition wall extended in the height direction at a center portion thereof so as to form a passage in two files.

Further, at least one or more auxiliary groove 16 a is formed between the adjacent coupling grooves 16A, and the auxiliary groove 16 a has the same shape as the coupling groove 16A, and the auxiliary groove 16 a is formed to be recessed inside the header 11A along a circumferential surface of the header 11A.

Further, the tank 12A further comprises a restricting protrusion 17A which is protruded inside the tank 12A so as to restrict insertion of an end of the bending portion 18A of the header 11A to a predetermined depth when the header 11A is inserted to the bending portion 19A of the tank 12A.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a and 1 c are exploded perspective views of a general heat exchanger.

FIG. 2 is a view of a conventional structure of a header-tank.

FIG. 3 is a view of a structure of a header-tank according to the present invention.

FIGS. 4 and 5 are cross-sectional views of the header-tank according to the present invention.

FIG. 6 is a view showing a restricting protrusion and a tap in detail.

FIG. 7 is a view showing positions of the restricting protrusion and the tap.

FIG. 8 is a view showing a process of forming the restricting protrusion.

FIG. 9 is a side view showing the position of the restricting protrusion.

FIG. 10 is a perspective view showing a coupled state between a header and a tank.

FIG. 11 is a view showing a header and a tank according to another embodiment of the present invention.

DETAILED DESCRIPTION OF MAIN ELEMENTS

10: header-tank 11: header 12: tank 13: tube insertion hole 14: end cap 15: tap 16: coupling groove 16a: auxiliary groove 17: restricting protrusion 18: bending portion 19: coupling portion 20: tube 30: fin

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a structure of header-tank for a heat exchanger according to the present invention is described in detail with reference to drawings.

FIG. 3 is a view of a structure of a header-tank according to the present invention, wherein FIG. 3A is a perspective view, FIG. 3B is a partially enlarged view and FIG. 3C is a side view. FIGS. 4 is a cross-sectional view of the header-tank according to the present invention, wherein FIG. 4A is a cross-sectional view taken along a line A-A′ of FIG. 3C and FIG. 4B is a cross-sectional view taken along a line B-B′ of FIG. 3C.

As shown in FIG. 3, a header-tank 10according to the present invention is formed by coupling a header 11 and a tank 12. The header 11 is formed with a plurality of tube insertion holes 13 extended in the transverse direction and arranged in the longitudinal direction. The header 11 is also formed with a bending portion 18 that is formed at both ends of the header 11 in the transverse direction and bent from a surface having the tube insertion hole 13 and then extended in the longitudinal direction. A plurality of taps 15 are formed at each end of the bending portion 18, as shown in FIGS. 3A and 3C.

The tank 12 is formed with a coupling portion 19 in which the bending portion 18 of the header is inserted. A coupling groove 16 is formed at the coupled portion 19 to be recessed in the longitudinal direction at the same position as the tap 15.

The coupling groove 16 is not extended over the entire girth of the tank 12 but extended only to a predetermined portion (i.e., side surface) of the coupling portion 19 of the tank 12. As shown in FIG. 3B, the tap 15 formed at the header 11 is bent over an end portion of the coupling groove 16 so as to fixedly couple the header 11 and the tank 12. At this time, since the end portion of the coupling groove 16 is formed to be recessed in the height, transverse and longitudinal directions, if the tap 15 is bent and anchored to the end portion of the coupling groove 16, binding force can be applied in all of the height and longitudinal directions.

In other words, according to a header-tank structure of the present invention, unlike in a conventional header-tank structure which cannot prevent the header and the tank from being slid in the longitudinal direction and thus deviated from their own positions since the tap in the conventional header-tank structure has the binding force in only the height direction, because the tap 15 and the coupling groove 16 in the header-tank structure of the present invention have the binding force in all of the height and longitudinal directions, it is fundamentally prevented that the tap 15 and the coupling groove 16 are separated in the height direction and also the tap 15 and the coupling groove 16 are slid in the longitudinal direction and thus deviated from their own positions.

As shown in FIGS. 3A and 3C, it is preferable that a auxiliary groove 16 a is further formed between the coupling grooves 16 to be recessed inside. The auxiliary groove 16 a may have the same shape as the coupling groove 16 (i.e., to be extended only to the predetermined portion of the coupling portion 19), or may be formed along an outer surface of the tank 12.

In case that the auxiliary groove 16 a is formed into the same type as the coupling groove 16, there is an advantage that it is possible to facilely perform the change of design, for example, by changing only an interval and position of the tap 15 of the header 11 as occasion demands.

However, in case that the header 11 and the tank 12 are respectively subjected to a force applied to the outside along the height direction, the separation of the header 11 and the tank 12 is prevented by the binding force due to the structure of the tap 15 and the coupling groove 16, but in case that the header 11 and the tank 12 are respectively subjected to a force applied to the inside along the height direction, since an upper side of the coupling groove 16 is opened, the binding force may be not occurred. Of course, since the header-tank 10receives the refrigerant having a relatively high pressure (comparing with the outside of the heat exchanger), substantially, it does not matter. However, one cannot completely rule out the possibility that the header-tank 10 is pressed in the height direction by an external force like an impact.

Therefore, the present invention further includes a protrusion 17 as shown in FIGS. 4 and 5. FIG. 4 is a cross-sectional view of the tank having a passage in single file and the structure of the present invention, and the FIG. 5 is a cross-sectional view of the tank having a passage in two files and the structure of the present invention, which is taken along the same line as FIG. 4B.

According to the present invention, the restricting protrusion 17 is formed inside the header 11 so as to restrict insertion of the tank 12 to a predetermined depth when the tank 12 is inserted inside the header 11. That is, in the structure of the header-tank of the present invention, the binding force against the force applied to the outside along the height direction is generated by the coupling of the tap 15 and the coupling groove 16, and also the binding force against the force applied to the inside along the height direction is generated by that the coupling portion 19 of the tank 12, which is inserted inside the bending portion 18 of the header 11, is stopped by the restricting protrusion 17 so as to be restricted to predetermined depth.

FIG. 6 shows the coupling groove, the restricting protrusion and the tap in detail. Since the restricting protrusion 17 is to prevent the coupling portion 19 of the tank 12 from being inserted inside the header 11 over the predetermined depth, it can be formed at any position on the bending portion 18 of the header 11 in the longitudinal direction. At this time, the restricting protrusion 17 may be formed in an alternate position which is not on the same line as the tap 15 (in the height direction), as shown in FIG. 6A. Alternatively, the restricting protrusion 17 may be formed on the same line as the tap 15, as shown in FIG. 6A.

Now, the first embodiment of FIG. 6A and the second embodiment of FIG. 6B are compared with FIG. 7. FIG. 7 is a view showing the position of the restricting protrusion 17 in the first embodiment of FIG. 6A. As shown in FIG. 5, since the coupling portion 19 of the tank 12 is stopped by the restricting protrusion 17, the coupling portion 19 is inserted only to a position that the restricting protrusion 17 is formed. After the position of the restricting protrusion 17 is fixed, a contact portion between the bending portion 18 of the header 11 and the coupling portion 19 of the tank 12 is braze-bonded. In FIG. 7, in the braze-bonded portion, i.e., a plane contact portion G, an upper side of the restricting protrusion 17 is designated by G₁ and the rest portion is designated by G₂. The plane contact portion G has a predetermined distance d in order to provide a sufficient strength when the plane contact portion G is braze-bonded (the distance d will be described later).

However, in case of the first embodiment of FIG. 6A, a height of the G₁ portion is “A” which is relatively smaller than that in the second embodiment of FIG. 6B. Since the G₁ portion in the first embodiment has the small height, it is structurally weak with respect to the external force. Meanwhile, the restricting protrusion 17 is formed by press-forming. At this time, since the G₁ portion in the first embodiment is structurally weak, deformation may be occurred undesirably as shown in FIGS. 7B and 7C. The braze-bonding has to be performed in the status that a lower side of the coupling portion 19 of the tank 12 is closely contacted with the plane contact portion G of the bending portion 18 of the header 11, however, if the G₁ portion is deformed so as to be protruded inside the header 11, a gap is generated between the header 11 and the tank 12, as shown in FIG. 7B, the braze-bonding cannot be normally done and thus there is the possibility of lowering a brazing strength.

That is, the restricting protrusion 17 may be formed in the position deviated from the tap 15 like in the first embodiment, but it is preferred that the restricting protrusion 17 is positioned along the same line as the tap 15. If the restricting protrusion 17 is formed at the position as described in the second embodiment, it is possible to minimize the deformation of the header 11 due to overlapped parts of members.

FIG. 8 is a view showing a process of forming the restricting protrusion 17. In the process, before forming the U-shape of the header 11, the restricting protrusion 17 is formed at a material by the press-forming. As shown in FIGS. 8A and 8B, the flat material is placed on a die having a groove of similar size and shape to the restricting protrusion 17 and pressed, thereby obtaining the flat material in which the restricting protrusion 17 is formed. Then, if the flat material is bent to form the bending portion 18, the molding of the header 11 is finished.

Of course, in the scope of the invention, the restricting protrusion 17 may be formed by other processes except the press-forming.

FIG. 9 shows the position of the restricting protrusion in detail. The tap 15 and the restricting protrusion 17 may be placed at any position selected by a designer. However, as shown in FIG. 9, in case that the tap 15 and the restricting protrusion 17 are formed on the same line, it is preferable that the tap 15 and the restricting protrusion 17 are formed between the tube insertion holes 13 along the longitudinal direction of the header 11.

If the position of the restricting protrusion 17 is overlapped with the position of the tube insertion hole 13, there is the possibility that the restricting protrusion 17 is contacted with the tube 20 inserted into the tube insertion hole 13 according to a height of the restricting protrusion 17. In this case, internal stress or strain may be formed between the parts. Furthermore, in case that the positions of the tap 15 and the restricting protrusion 17 are overlapped with the position of the tube insertion hole 13, it is difficult to secure a working space. Therefore, in case that the tap 15 and the restricting protrusion 17 are formed on the same line, the tap 15 and the restricting protrusion 17 are formed between the tube insertion holes 13 along the longitudinal direction of the header 11, thereby previously preventing the above problems.

FIG. 10 shows a coupled state between the header and the tank in detail. As shown in the drawing, the coupling groove 16 is formed along the girth of the tank 12 to be recessed inside the tank 12. The coupling groove 16 and an outer surface of the tank 12 are connected with each other through an inclined surface S having a predetermined angle. Of course, they can be connected through a vertical surface. However, since the coupling portion 19 of the tank 12 is formed by bending the flat material and the coupling groove 16 is formed by the press-forming, if the coupling groove 16 and the outer surface of the tank 12 are formed to be connected through the vertical surface upon the press-forming, there are some problems that the connection surface may be seriously strained, the connection surface may be damaged in the press-forming process, or at least the strength may be deteriorated considerably. Accordingly, it is preferable that the coupling groove 16 is surrounded by the inclined surface S having a predetermined angle. As described above, the coupling groove 16 is formed by pressing the outer surface of the tank 12. At this time, the inclined surface S can be naturally formed by a shape of a working tool. In addition, the inclined surface S surrounding the coupling groove 16 forms a hook portion 16 b which is contacted with the bent tap 15 so as to prevent the separation of the header 11 and the tank 12.

Preferably, the bending portion 18 is placed at a lower side of the coupling groove and the inclined surface S surrounding the coupling groove 16. In other words, in case that the bending portion 18 is formed to be extended to the position of the coupling groove 16, there is a problem as follows. In the status that the bending portion 18 is closely contacted with a side surface of the coupling groove 19, the braze-bonding is performed to fixedly couple the bending portion 18 and the coupling portion 19. In case that the bending portion 18 is extended to the position of the coupling groove 16, a part of the bending portion 18 is not contacted with the coupling portion 19 due to a space fromed by the coupling groove 16 and thus this part is not braze-bonded. However, if an empty space is formed at the braze-bonded portion, brazing stability may be lowered remarkably. Therefore, it is preferable that the bending portion 18 is extended only to a lower portion of the coupling groove 16.

Further, the bending portion 18 is formed so that the predetermined distance d for the braze-bonding is formed between an end of the bending portion 18 and an end of the restricting protrusion 17 which is placed at the side of the bending portion 18. This distance d forms the plane contact portion G, and also this distance d may be formed properly according to various design parameters such as a size of the header-tank 10, a feature of the refrigerant to be flowed in the header-tank 10, an internal pressure applied to the header-tank 10 and the like.

Preferably, the tap 15 is formed to be equal to or greater than a width R of the inclined surface S, thereby providing the stable binding force between the tap 15 and the coupling groove 16 when the tap 15 is bent to the coupling groove 15.

FIG. 11 is a view showing a header and a tank according to another embodiment of the present invention.

In FIGS. 3 to 10, the tap 15 and the restricting protrusion 17 are formed at the bending portion 18, and the coupling groove 16 is formed at the coupling portion 19 of the tank 12. However, in the embodiment of FIG. 11, the tap 15A and the restricting protrusion 17A are formed at the coupling portion 19A of the tank 12A, and the coupling groove 16A is formed at the bending portion 18A, and also in this case, the tap 15A is bent and then hooked by the hook portion 16 bA formed at an end of the coupling groove 16A thereby increasing the binding force in the height direction.

Althought the positions of the tap and the coupling groove are exchanged, the header 11A may have a partition wall so as to a passage in two files, as shown in FIG. 5. Therefore, this embodiment can be applied to the various structures of FIGS. 3 and 10.

INDUSTRIAL APPLICABILITY

Due to the structure according to the present invention, when coupling the tank and the header of the heat exchanger, it is possible to restrict a relative movement of the header and the tank in the longitudinal direction, and at the same time, it is possible to increase the durability of the header-tank. Further, according to the present invention, since the tap is formed to be extended only to the coupling groove, it is possible to remarkably reduce a length of the tap comparing with the conventional tap which is extended to a horizontal plane of the header or the tank, and thus it is possible to considerably save the materials and also reduce the manufacturing cost.

In addition, according to the present invention, since the tank is formed with the coupling groove and the auxiliary groove, it is possible to facilely perform the change of design, for example, by changing only an interval and position of the tap of the header as occasion demands. Furthermore, since the auxiliary groove is formed at the tank, it is possible to structurally increase the strength of the tank.

Those skilled in the art will appreciate that the conceptions and specific embodiments disclosed in the foregoing description may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. Those skilled in the art will also appreciate that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims. 

1. A structure of header-tank for a heat exchanger, comprising: a plurality of tubes which are arranged in a row along an air-blowing direction to be spaced apart from each other at a certain intervals; fins which are interposed between the tubes so as to increase a heat exchange surface area with respect to air flowing between the tubes; and a pair of header-tanks which comprises a header having a tube insertion hole and a tank coupled with the header and in which heat exchange medium is flowed, wherein the header is bent at a surface, in which the tube insertion hole is formed, so as to form a bending portion in a height direction, and the bending portion is formed with a plurality of taps, and the tank is formed with a coupling portion coupled to the bending portion of the header, and a coupling groove which is recessed inside tank at the same position as the tap along a longitudinal direction and in which the tap is bent and inserted.
 2. The structure of header-tank as set forth in claim 1, wherein the header is formed by bending a single plate material so that the bending portion is formed at both ends, and provided with a partition wall extended in the height direction at a center portion thereof so as to form a passage in two files.
 3. The structure of header-tank as set forth in claim 1, wherein at least one or more auxiliary groove is formed between the adjacent coupling grooves.
 4. The structure of header-tank as set forth in claim 3, wherein the auxiliary groove has the same shape as the coupling groove.
 5. The structure of header-tank as set forth in claim 3, wherein the auxiliary groove is formed to be recessed inside the tank along a circumferential surface of the tank.
 6. The structure of header-tank as set forth in claim 1, wherein the header further comprises a restricting protrusion which is protruded inside the header so as to restrict insertion of an end of the coupling portion of the tank to a predetermined depth when the tank is inserted to the bending portion of the header.
 7. The structure of header-tank as set forth in claim 6, wherein the restricting protrusion is formed by press-forming.
 8. The structure of header-tank as set forth in claim 6, wherein the restricting protrusion is formed between the taps of the bending portion.
 9. The structure of header-tank as set forth in claim 6, wherein the restricting protrusion is formed at a lower side of the tap in the longitudinal direction.
 10. The structure of header-tank as set forth in claim 9, wherein the tap and the restricting protrusion are formed at an area of the bending portion 18, which is placed between the tube insertion holes 13 in the longitudinal direction.
 11. The structure of header-tank as set forth in claim 1, wherein the coupling groove is connected with an outer surface of the tank through an inclined surface S.
 12. The structure of header-tank as set forth in claim 11, wherein the inclined surface S surrounding an end of the coupling groove forms a hook portion which is contacted with the bent tap so as to prevent the header and the tank from being separated.
 13. The structure of header-tank as set forth in claim 11, wherein an end of the bending portion is placed at a lower side of the inclined surface and the coupling groove so as to prevent the bending portion from being overlapped with a lower portion of the inclined surface S and the coupling groove of the tank.
 14. The structure of header-tank as set forth in claim 11, wherein the bending portion is formed with a plane contact portion having a predetermined distance, which is provided between an end of the bending portion and an end of the restricting protrusion.
 15. The structure of header-tank as set forth in claim 11, wherein the tap is formed to be equal to or greater than a width of the inclined surface.
 16. A structure of header-tank for a heat exchanger, comprising: a plurality of tubes which are arranged in a row along an air-blowing direction to be spaced apart from each other at a certain intervals; fins which are interposed between the tubes so as to increase a heat exchange surface area with respect to air flowing between the tubes; and a pair of header-tanks which comprises a header having a tube insertion hole and a tank coupled with the header and in which heat exchange medium is flowed, wherein the header is bent at a surface, in which the tube insertion hole is formed, so as to form a bending portion in a height direction, and the bending portion is formed with a plurality of coupling groove formed to be recessed inside the header, and the tank is formed with a coupling portion coupled to the bending portion of the header, and a tap which is formed at the same position as the coupling groove along a longitudinal direction so as to be bent to and inserted into the coupling groove.
 17. The structure of header-tank as set forth in claim 16, wherein the header is formed by bending a single plate material so that the bending portion is formed at both ends, and provided with a partition wall extended in the height direction at a center portion thereof so as to form a passage in two files.
 18. The structure of header-tank as set forth in claim 16, wherein at least one or more auxiliary groove is formed between the adjacent coupling grooves.
 19. The structure of header-tank as set forth in claim 16, wherein the tank further comprises a restricting protrusion which is protruded inside the tank so as to restrict insertion of an end of the bending portion of the header to a predetermined depth when the header is inserted to the coupling portion of the tank. 